What's the min temp your area considers a heatwave and what's the max temp your area considers to be a Cold Snap? (warm, average)

[Jas182]

Just a little interested in what areas around the world would consider a heatwave to be, and what those areas consider a cold snap to be? If you want, also feel free to give what you believe to be a heatwave and cold snap in your personal opinion?
So here's my areas, my countries capital, and my personal opinion of what the min temps should be to be considered a heatwave, and what the max temps should be to be considered a cold snap:

South East of England:
Heatwaves to be at least: a max of 31C (88F) and a min of 16C (61F), and lasting for 48 hours or more.
Cold Snaps to be at least: Mean Temps below 2C (36F), and lasting for more than 48 hours.

London:
Heatwaves to be at least: a max of 32C (90F) and a min of 18C (64F), and lasting for 48 hours or more.
Cold Snaps to be at least: Mean Temps below 2C (36F), and lasting for more than 48 hours.

For me personally:
Heatwaves to be at least: a max of 38C (100F) and a min of 25C (77F)
Cold Snaps to be at least: a max of 10C (50F) and a min of 5C (41F) - so basically all of winter in the UK is a cold snap for me, on average!

[Rams_Lord]

Sweden

Heatwave: 5 consecutive days above 25C (77F)
Cold snaps: I don't think our meteorological institute has a definition for a cold wave, but I'm guessing it'd be 5 consecutive below -10 to -15C

I'd say a heatwave for me is 5 consecutive days above 22C , and I don't really have a threshold for a cold snap

[Shalop]

Long Island, NY, USA:
Heatwave - three consecutive days where the high temperature reaches 90F (32.2C) or higher.
Cold snap - no official definition. A reasonable definition is probably "three consecutive days with high temperatures below 32F (0C)"

For me:
Heatwave: two consecutive days above 85F (29C).
Cold Snap: four consecutive days with high temps below 5F (-15C); this never happens in most parts of the contiguous USA.

[chicagogeorge]

NWS HEAT WARNING CRITERIA FOR U.S.

- Excessive Heat Outlook and Watch: Potential for Excessive Heat Warning

- Heat Advisory: Heat index of 105(degrees) for 3 hours and an overnight low of 75(degrees) or higher



- Excessive Heat Warning: Heat Index of 115(degrees) for 3 hours or a heat index of 105(degrees) for 3 days

HEAT WARNING CRITERIA FOR CHICAGO

After lessons learned from the 1995 heat wave tragedy in Chicago, individual cities in the U.S. have developed their own warning criteria. One important point is that heat effects are cumulative and include high nighttime lows.

- 3 days with heat index of 100-105(degrees) with 85% sunshine and nighttime lows above 75(degrees) or

- 2 days with a heat index of 105-110(degrees) or

- 1 day with a heat index greater than 110

The heat index and heat warning criteria - Chicago Tribune



Wind chill advisories/warnings for Chicago

Wind Chill Warning - Extreme wind chills of -30F or colder.
A Wind Chill Warning is issued when the wind chill will be less than or equal to -30F AND winds greater than or equal to 10 mph.
Wind Chill Advisory - Dangerous wind chills of -20F to -30F.
A Wind Chill Advisory will be issued when the wind chill is less than or equal to -20F AND the winds are greater than or equal to 10 mph.

http://www.crh.noaa.gov/lot/?n=winter

[tenkier7]

Central North Carolina:

Heatwaves:
Maximum temperature above 100°F(38°C)
Maximum temperature above 95°F(35°C) for 5 consecutive days or more
Minimum temperature above 77°F(25°C)

Coldwaves:
Maximum temperature below 40°F(4°C) for 3 consecutive days or more
Maximum temperature below 32°F(0°C)
Minimum temperature below 20°F(-7°C)



Personal Observation:

Heatwaves:
Maximum temperature above 95°F(35°C)

Coldwaves:
Minimum temperature below 5°F(-15°C)

[L.A.-Mex]

heatwave here is at least 5 or more days of 100 F+

coldwave here is at least 5 or more days of lows below 45 F. (paired with days in the 60s)

[BullochResident]

By southern Georgia standards-

Heatwave (summer): Multiple days in a row in the triple digits. 95F is pretty common here, but 100F+ is not due to the high levels of humidity acting as a buffer.

Coldwave (winter): 2 or more consecutive days where the afternoon temp fails to reach 50F. Happened earlier this week, and it's only freaking November...

[Joe90]

I haven't heard the term heatwave used around here, but I'm guessing most people would consider 3-4 days above 25C/77F, to be a warm spell. No minimum temperature really. Here tends to just get a few warm nights from time to time.

Cold spells would be 2-3 days with minimums below about - 3C/26F, with maximums around 10C/50F, or even colder.

[Thunder98]

Heat Wave: High of 85F for 2 or more consecutive days
Cold Wave: Morning low of 32 degrees for 2 or more consecutive days

By Central California Coast Standards

[Jas182]

Originally Posted by Joe90

I haven't heard the term heatwave used around here, but I'm guessing most people would consider 3-4 days above 25C/77F, to be a warm spell. No minimum temperature really. Here tends to just get a few warm nights from time to time.

Cold spells would be 2-3 days with minimums below about - 3C/26F, with maximums around 10C/50F, or even colder.

Hmmm, would have thought places like New Zealand would still have quite a view heatwaves, considering the latitude... Maybe it's cus the country is surrounded by sea?